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United States Department of Agriculture

Agricultural Research Service


Location: Children's Nutrition Research Center

Title: Lactation biology symposium: Circadian clocks and photoperiod in mammary gland development and lactation

item Hadsell, Darryl

Submitted to: Journal of Animal Science
Publication Type: Proceedings
Publication Acceptance Date: 2/24/2012
Publication Date: 3/1/2012
Citation: Hadsell, D.L. 2012. Lactation biology symposium: Circadian clocks and photoperiod in mammary gland development and lactation. Journal of Animal Science. 90(3):742-743.

Interpretive Summary:

Technical Abstract: Life on earth evolved with light-dark cycles. As a result there arose in all organisms, though probably first in photosynthetic archaebacteria, oscillatory mechanisms to time processes that were necessary for survival and reproduction. The first known account of these oscillations was given for plants in the 4th century BC by Androsthenes, a ship captain under Alexander the Great. It was not until the early 20th century, however, that the presence of or about 24-h patterns of activity in the absence of external queues was observed in mammals. In 1959, Franz Halberg coined the term circadian from the Latin words "circa" (about), and "dies" (day) to describe these of or about 24-h oscillations that are now known to occur in all living organisms. The development of the mammary gland and lactation are subject to regulation by a set central and peripheral clock molecules that appear to be conserved across species. The work presented provides a useful basis for further studies aimed at understanding how peripheral Clocks regulate the various aspects of mammary gland development and what their potential role is in determining milk production. It is only a matter of time.

Last Modified: 06/25/2017
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